1. Field of the Invention
The present invention is broadly concerned with an improved method for analyzing soil samples in order to ascertain the physical properties thereof. More particularly, the invention pertains to such a method wherein, in one aspect, a soil sample having essentially undisturbed, naturally occurring compaction and stratification properties is analyzed for water infiltration rate, water holding capacity and porosity; the sample is then divided into a plurality of strata which are individually analyzed for sand, silt, clay and organic content. The method of the invention yields data which can accurately pinpoint problem areas in the soil which would not be determinable by conventional techniques.
2. Description of the Prior Art
Soil testing techniques have long been employed for the analysis of turf and seed beds. For example, golf course green's keepers routinely send seed bed samples to laboratories in an effort to determine the condition of the seed bed. It is believed that such tests aid the green's keeper in determining the proper course for maintenance of the seed bed, e.g., the need for soil aeration, watering schedules and/or chemical applications.
Conventional soil testing techniques used for these purposes have involved the step of first "plugging" the soil to obtain a vertical soil sample of perhaps 4 inches in height. Such a sample plug is then sent to the lab for analysis. The first laboratory step involves pulverizing the plug below the thatch layer with mixing to create a homogenized soil sample. This homogenized soil is then compacted by the laboratory into a laboratory plug which is analyzed by known techniques for water filtration rate, water holding capacity, and porosity. In addition, the homogenized, laboratory compacted plug is analyzed for textural properties including sand, silt and clay contents.
A persistent problem in the art is that such conventional soil plug tests do not yield realistic results which can be used to develop a seed bed maintenance program. That is, a conventional battery of tests may lead to the conclusion that the seed bed is in perfectly acceptable condition; yet, the green's keeper knows from experience that the seed bed has problems, usually resulting in sparse grass cover and lackluster growth in hot, dry weather. When soil tests seemingly indicate that the seed bed is within acceptable limits, the green's keeper often concludes that the problem is of a chemical rather than of a physical nature. This may lead the green's keeper to overapply fertilizers or herbicides, which can in fact actually exacerbate the real problem.
Soil compaction is recognized as one of the major problems to be overcome in producing good turf. This is particularly true on golf courses where player traffic and maintenance equipment subjects the soil to constant packing. The fact that golfers demand that grasses be kept moist enough to hold a golf shot serves to intensify the compaction problem. However, as explained above, conventional soil testing methods do not and cannot actually measure in any meaningful way the real compaction of soil samples. This stems from the fact that conventional testing requires that a given field sample be first pulverized, mixed and laboratory compacted. As a consequence, the actual conditions of the soil are often not reported by the known testing techniques.
There is accordingly a real and unsatisfied need in the art for an improved soil testing method which gives results which more closely approximates actual, real world seed bed conditions.